Driving mechanisms



Feb; 3, 1959 v, HARTY I 2,872,183

DRIVING MECHANISMS Filed March 12, 1956 5 Sheets-Sheet 3 Feb. 3, 1959 R. v. HARTY DRIVING MECHANISMS 5 Sheets-Sheet 4 Filed March 12, 1956 Feb. 3, 1959 R. v. HARTY DRIVING MECHANISMS 5 Sheets-Sheet 5 Filed Marh 12, 1956 p 7 Full/s IN? T DRIVING MECHANISMS Ralph V. Harty, Detroit, Mich, assignor to R. V. Hart Cm, Ino, Detroit, Mich a corporation of hiichigan Application March 12, 1956, Serial No. 576367 7 Claims. (Cl. 268-53) This invention relates to actuators generally and more specifically to actuators particularly adapted for use with door constructions.

It is an important object of the invention to provide an improved actuator adaptable to widely different applications where a motive source is required and which has incorporated in its operation a reiiable and eflicient safety feature.

it is another important object of the invention to provide an improved actuator which is particularly adapted for the operation of doors, which is adapted to actuate doors of a wide variety of types and sizes, and which incorporates an'improved automatic safety feature.

Still other important objects of the invention are to provide an improved door'actuator which is constructed and arranged with respect to the door construction so as to be movable bodily when obstruction to movement of the door is experienced; to provide in association with the door actuator sensing means responsive to. movement of the door actuator, whereby to prevent injury to persons or damage to'property; to provide the door actuator in the form' of a rigid unitary assembly which is versatile and suitable for simple'attachment to door constructions of varied design; to provide in combination with the door actuator means to pivotaliy suspend the assembly about an axis and to bias the same in a central position during normal operation and during an abnormal occurrence, to permit pivoting of the assembly from the central position by more than ordinary reactive torque to activate the sensing means so as to de-energize the door actuator; and to provide a door actuator which is compact, rugged of construction, durable and reliable in operation.

The above and other objects of the invention will become' apparent during the following description, reference being, had to the accompanying drawings, wherein a preferred embodiment of one form of the present invention is clearly shown.

In the drawings:

Figure l is a front elevation of a vertical lift door construction with the door actuator embodying the present invention operatively associated therewith;

Fig. 2 is a vertical section shown broken substantially on the line 2.-2 of Fig. 1;

Fig. 3' is an enlarged view of certain parts of Fig. 1 showing the door actuator in more detail;

Fig. 4 is a left-hand side View of the structure of Fig. 3;

Fig; 5 is a front elevation of a rolling door construction with the door actuating means embodying the present invention operatively associated therewith;

Fig. 6 is a plan view of the structure of Fig. 5;

Fig. 7 is an enlarged view of certain parts of the structure of Fig. 5 showing in greater detail the arrangement of the door actuating means;

Fig. 8 is a left-hand side view of the structure of Fig. 7 with the cover plates removed;

Fig; 9is a fragmentary view in elevation, being broken,

2,872,183 Patented Feb. 3, 1959 ice ' design ted 11 for rotating input shaft 37 of speed reducing means including a gear box 17, the output shaft of which is designated 15. The motor means and speed reducing means are constructed and arranged as a rigid unitary assembly. This entire assembly is dependingly pi orally supported from a horizontal driving shaft 45 for the door mechanism, to which shaft the assembly is attached by a coupling member 19 to pivotally suspend the assembly about an axis. Biasing means, generally designated 21, retains the assembly in a central position during normal operation. The biasing means is constructed and arranged to permit the assembly to pivot about its axis of suspension from a reactive torque deveioped from obstruction to movement of the door construction. Associated with the assembly are sensing means, generally designated 23, responsive to rotation of the assembly, and means responsive to the sensing means to de-energize the motor means 11. The door actuator, in addition, includes brake means 25, preferably electric brake means, to lock the movable parts of the door actuator and the door construction when the motor means 11 is tie-energized. Optionally, and in most instances, the door actuator also comprises manual means including a hand chain 27 for hand operation of the door construction through clutch means, generally designated 23, and means to operatively relate the clutch means to the output shaft 15. The manual means also includes disconnect means, generally designated 31, to take out of circuit the motor means and means to put oif the brake means 25 when hand operation is employed.

Referring to the structure in more detail, the motor means ii is suitably mounted on a base plate 33 which is fastened to the gear box 17' so that the two form a rigid assembly. A belt 35 transmits power from the motor shaft 13 to the input shaft 37 of the gear box. Within the enclosure of the gear box 17 are two additional shafts 39, 3%, parallel. to the input shaft 37, to each of which is suitably keyed a spur gear 41, 41a, a similar gear 41b being keyed on output shaft 15 and the gears being driven in a well-known manner by pinions 42, 42a, 4-21), respectively, to reduce the rotational speed between the input shaft 37 and the output shaft 15 of the gear box 17. It will be observed that all of the shafts are parallel, the gear drive is reversible, and that consequently any change in the load upon the output shaft imposes a reactive torque on the gear box concentric with the output shaft.

The supporting means 19 for the door actuator can take the form of any number of Well-known constructions adapted to pivotally support an object, and in the structure shown in Fig. 3, the supporting means comprises a coupling member 45 which is keyed or otherwise secured to the output shaft 15 of the door actuator gear system and tothe main drive shaft 46 for the vertical lift door construction, the latter being shown best in Figs. 1 and 2.

The biasing means 21 is connected between the door actuator and a suitable fixed structural part as 59 appurtenant to the particular door construction with which the actuator is associated. The biasing means preferably comprises a rigid member, generally designated 47, pivotally connected to the door actuator and a rigid member 49 secured to the door construction. The rigid member 49 for the particular vertical lift door construction shown is in the form of an angle plate secured at 3 one end to one of the upright support members 59 for the counterweight tower 60, which will be more particularly described hereinafter. Between the rigid member 47 and the rigid member 49 is resilient means preferably in the form of a centering spring 51 which biases the door actuator in a central position during normal operation. The rigid member 47, which is connected to the door operator, is preferably in the form of an eye-pin 53 which extends slidably through an aperture in a flange 55 of the rigid member 49 and is pivotally secured at the eye thereof to a pivot pin 54 secured to the base plate 33. The centering spring 51 is slidably fitted over the shank of the eye-pin 53 to the right of the flange 55, as viewed in Fig. 3, and operates both in tension and compression, its left end being secured to the flange 55 and its right end to the retainer 57 fastened to the eye-pin. The spring thus biases the door actuator in a central position against ordinary reactive torque developed during normal operation. In the event that an unusually high load is imposed on the output shaft, due, for example, to an obstruction to movement of the door, the entire assembly will pivot about the output shaft. This pivoting will occur in one directionif an obstruction is experienced during opening, and in the opposite direction if the obstruction occurs during closing. Pivoting of the assembly from its central position is due to the greater than ordinary reactive torque developed about the output shaft 15 in opposition to the torque of the motor means 11 from the obstruction to movement of the door construction, in the case of opening movement,

and in the case of closing movement, to the fact that if the door is blocked, the motor is required to lift the counterweights without the aid of the weight-of the door. This greater than ordinary reactive torque overcomes the resistance of the centering spring 51 and moves the assembly in one direction or another. Assuming, for purposes of explanation, that in Fig. 3 the direction of pivoting of the assembly from reactive torque is clockwise (about the axis of shaft 15) when the obstruction or jamming of the doors occurs in closing, then the centering spring 51 will be placed under compression by the movement of the retainer member 57, connected to the,

door actuator, toward the flange of rigid member 49, connected to the door construction. It the obstruction occurs when the door construction is being opened the assembly will pivot from reactive torque about its axis of suspension in a counterclockwise direction and the centering spring 51 will be placed under tension due to the movement of the retainer member 57 away from the flange 55 of rigid member 49. During normal operation of the door actuator in overcoming friction in a balanced system, the centering spring 51 absorbs ordinary reactive torque developed thereby including starting and stopping torque so as to maintain the assembly in a central, substantially stationary position. The characteristics of the centering spring 51 arechosen taking into consideration, among other factors, the particular application, the weight of the assembly, and the h. p. of the motor means.

The sensing means 23 cooperates with the biasing means and is responsive to the movement of the door actuator from its central position. The sensing means comprises a microswitch 61, the plunger 63 of which remains in contact with the door actuator in its central position. The microswitch 61 is stationary and secured to the door frame construction although it may also be secured to the assembly as a part of the door actuator. In the particular door construction shown in Figs. 1-3, the microswitch 61 is mounted on an angle plate 62 which in turn is secured to the rigid member 49. The plunger 63 of the microswitch 61 is spring-biased in known manner to follow the movement of the door actuator. When the door actuator is in its central position, the contacts of the microswitch 61 are in closed position and when the plunger 63 of the microswitch is moved by movement of the door actuator assembly, the contacts of the microswitch 61 are open. Opening of the contacts of the microswitch de-energizes the motor and thereby stops the movement of the moving parts of the door construction. Adopting the assumption previously made for purposes of explanation, the plunger 63 would be moved away from the body of the microswitch 61 when the door actuator is rotated in a clockwise direction and would be moved into the body of the microswitch 61 when the door actuator is rotated in a counterclockwise direction. In following the movement of the door actuator, the plunger 63 causes the contacts of the microswitch to open in any of its positions but the central position thereof.

The housing 65' for the electric brake means 25 is secured both to the gear box 17 and the base plate 33 and is therefore an integral part of the rigid assembly of the door actuator. The operative parts of the electric brake means within the housing 65 are not shown as they may be of conventional construction and include, as is well known, a brake solenoid in shunt with the motor means. The brake solenoid is energized concurrently with the motor means and automatically pulls the brake off against the effort of an applying spring (not shown) when the motor means is energized. Mechanical means are also provided to disengage the brake including a horizontal bar generally designated 67 which is pivotally secured at one side of the brake housing as at 69 and extends through the same so that the free end 71 thereof projects from the other side of the brake housing. A spring 73 is secured at one end to the gear box 17 by an angle plate 75 and at the other end to the bar 67 so as to urge the bar upwardly about the pivot means 69. When bar 67 is in its normal up position it does not interfere with normal operation of the brake, which whenever the motor is de-energized applies a frictional force to the brake drum 77 shown secured to the input shaft 37 of the gear box 17. The brake locks the input shaft 37 against rotation, which shaft in turn holds the moving parts of the door construction and the door actuator.

For taking the brake off manually when it is desired to hand operate the door construction, as in the event of a power failure, the disconnect means 31 is actuated by a portion 79 of a disconnect chain 81 which extends to within reach of floor level. Downward force applied to the disconnect chain 81 pulls the bar 67 away from the top plate of the brake housing against the urging of the spring 73 and mechanically releases the brake. For this purpose the bar 67 may be provided within the brake housing with a suitable cam (not shown) to urge the shoe structure away from the drum when the bar is pulled down. The disconnect means also includes an additional safety feature in the form of a microswitch 83 secured to the angle plate 75 and which is actuated by movement of the bar 71. The contacts of the microswitch 83 are in series'with the motor means and are opened by movement of its plunger 85 which is biased against the bar 71. This insures that the motor means 11 cannot be energized when hand operation of the door construction is being employed. Another portion 37 of the disconnect chain 81 branches therefrom below the door actuator and extends over a suitable pulley 89 to engage the manualdrive clutch means 29.

The manual-drive clutch means 29 includes a sprocket wheel 91 which is secured to a shaft 93 mounted in bearings on a pair of parallel mounting plates 95, 97. Sheet metal guard plates 99 are secured to the mounting plates 95', 97 and extend around the sprocket wheel 91. The mounting plate 95 is secured to an angle iron 101 which in turn is pivotally secured to an angle iron 103 by a shaft 195. The angle iron 103 is secured to the gear box 17 so that the clutch means is an integral part of the door actuator assembly. The sprocket wheel 91 is 5. rotated by the hand chain 27 which extends to within reach of the floor. The sprocket wheel 91 has a stud 107 secured thereto which protrudes laterally from the sprocket wheel and engages means on pulley wheel 109, as for example, the spokes of the pulley wheel, to rotate the same. The pulley wheel 169 normally transmits power from the motor shaft 13 and is approximately of the same size as the sprocket wheel $1. But when the motor means is de-energized by the disconnect means 31, and clutch means 29 is engaged, the pulley wheel 109 transmits power from the sprocket wheel 91 to the output shaft 15 of the door actuator. Downward force exerted on the disconnect chain 81 through the portion 87 pivots the clutch means 29 toward the pulley wheel 109 and the stud 107 engages the spokes on the pulley wheel. The hand chain 27 is then operatively connected to the main drive shaft 45 for the door construction for manual actuation of the same. Downward force must be continued to be exerted on the disconnect chain 81 while the hand chain 27 is being pulled in order to put off the brake means, take out of circuit the motor means, and engage the clutch means. To facilitate application of a steady downward force on the disconnect chain 81, springs 111 and 113 are made part of the linkage of the portions 79 and 87, respectively, of the disconnect chain 81.

The door actuatoris shown mounted in position to actuate a conventional vertical lift door construction in Figs. 1 and 2. The vertical lift door construction is adapted to open and close a door opening, located as indicated by the numeral 114. The lintel of the door opening is generally designated 115. A pair of doors, an upper door 117 and a lower door 119, operate one behind the other in a space in front of the door opening 114. Adjacent the pair of doors to one side of the door opening, is the counterweight tower 61), in which a pair of counterweights 123, 125 operate. The counterweight 123 is connected to the upper door 117 by a pair of cables 127, 127'. The cable 127 has one end thereof secured to the top of the counterweight tower as at 129, and passes under a pulley 131 which is journaled in a pickup leaf 133 attached to the top of the upper door 117 adjacent the vertical edge thereof closest to the counterweight tower. The other end of the cable 127 is secured to the counterweight 123, as at 135, after passing over the sheave 137. In a similar manner, the cable 127 has one end thereof secured to the top of a fixed structural part on the side of the door opening farthest from the counterweight tower, as at 129, and passes under a pulley 131 which is journaled in a pickup leaf 133' attached to the top of the upper door 117 adjacent the vertical edge thereof opposite the edge adjacent pickup leaf 133. The other end of the cable 127 is secured to the same counterweight 123, as at 135- after passing over the sheave 137. Cable 127 also passes over a sheave 128 (not shown) at the top of the door construction on the side opposite from the counterweight side of the door opening. The sheave 128 is in line in a vertical plane with the previously mentioned sheave 137. The counterweight 125 is secured to the lower door 119 by a pair of cables 139, 139'. The cable 139 is directly secured to a pickup leaf 14-1 fastened to the top of the lower door 119 on the counterweight side of the door opening. The other end of the cable 139 is secured to the counterweight 125, as at 143, after passing over the sheave 145. In a similar manner, the cable 139' is directly secured to a pickup leaf 141 fastened to the top of the lower door 119 adjacent the vertical edge thereof opposite pickup leaf 14 1. The other end of the cable 139 is secured to the counterweight 125 as at 143 after passing over the sheave 145. In a vertical plane with the sheave 145' is a sheave 149 over which the cable 139' also passes at the top of the door construction. The sheave 141) is secured to the same shaft 142' as the sheave 128. The shaft 142' is suitably mounted at the top of the door construction by a pair of parallel plates, one of which, 144, is shown in Fig. 1. The double pair of sheaves 137, 137 and 145, 145 are secured on the main drive shaft 4-5 for' the door construction. drive shaft is rotatably moun ed in a pair of pillow blocks 147, 149 which are secured to a pair of spaced channel:

irons 1531, 153 mounted on the top of the counterweight tower 121.

The pair of doors and the pair of counterweights to which they are secured constitute a balanced system and the function of the door actuator is to overcomefriction in the system whereby to raise or lower the doors, dethe direction of'rotation of the motor means motor will rotate in one direction upon actuation of theup-button, for example, on the starter switch and in the opposite direction upon activation of the down-button on the starter switch. The motive power from the motor means 11 is transmitted from the motor shaft 13 to the input shaft 37 of the gear box and through the plurality of gears in the gear box tothe output shaft 15 of the door actuator which is directly coupled to-the main'drive shaft 4 5 for the door construction. Rotation of the main drive shaft 45 causes the double pair of sheaves 137, 137' and 1 15, 145' to rotate whereby to pull the cables 127 and 127 for the upper door 117 and the cables 139 and 139' for the lower door 119 in one direction or the other, de pending upon the direction of the rotation of the motor means.

Since the door actuator is pivotally suspended about its output shaft, a greater than ordinary reactive torque developed from obstruction to the movement of either of the doors will cause the door actuator to pivot about its output shaft in the manner described and cause the plunger 63 of the microswitch 61' to open the contacts in the circuit of the motor means, thereby immediately stopping'further movement of the doors to prevent injury to persons or damage to property. Assuming that the main drive shaft 45 is rotated in a clockwise direction, as viewed in Fig. l, to raise the pair of doors so as to open the door opening, then in the event of an obstructionto movement of either of the doors while they are being raised, a downward force will be exerted on the cables fastened to the door that experiences the obstruction. This downward force will result in a more than ordinary torque applied to the main drive shaft 45 in opposition to the output torque applied thereto by the motor means of the door actuator. door actuator to rotate in a counterclockwise direction as viewed in Fig. 1. 1n the event of an obstruction to either of the doors in their downward movement, in which case the main drive shaft 45 is rotating in a'counterclockwise direction to close the door opening, the counterweight for the particular door that is obstructed must be raised solely by the door actuator and because this force is considerably greater than the frictional force which the door actuator normally overcomes, the counterweight for the door which is obstructed will exert a downward force and thereby develop a more than ordinary torque about the main drive shaft 45 in opposition to the torque applied thereto by the door actuator. This reactive torque will cause the door actuator to rotate about its output shaft in a clockwise direction, as viewed in Fig. 1. Actually, only slight rotation of the door actuator occurs before the motor means 11 is deenergized. This is due to the resilient action of the centering spring 51 which normally biases the door actuator inits central position and the location of the sensing means 23, whereby only slight movement from the central position caused by an obstruction causes the plunger 63 of the microswitch 61 to open its contacts to de-energize the motor means. This safety feature of the door actuator is especial-1y sensitive since only slight movement thereof is required to de-energize the motor means and an obstruction, for example, caused by an object leaning against one of the doors will be sufficient to de-energize the motor means. Because the door actuator is compact and contains within The main The circuitry for the motor means is such that the This reactive torque will cause the its assembly a plurality of operatively related means constructed and arranged to require a minimum of maintenance it can be mounted readily in remote places and, if need be, operated conveniently and manually by the combination of the disconnect chain 81 and the hand chain 27.

Figs. 5, 6, 7 and 8 show the versatility of the door actuator in a unique arrangement for opening and closing a doorway indicated by the numeral 154 with an extra heavy soundproof door construction which is adapted to roll across the doorway. In the structure shown, the vertical sides of the doorway 154 are displaced in a vertical plane as can be seen from the plan view of Fig. 6 wherein the side 155 projects from the doorway a greater distance than the side 157 to accommodate the door construction, generally designated 159, which is in this instance wedge-shaped with its narrowest side 161 and its widest side 163 abutting the sides 155 and 157 of the doorway, respectively. The door construction 159 comprises a plurality of horizontal I-bearns 165 mounted one above the other and secured thereto are strut members 167 which form the framework for the general wedgeshape of the door construction. Other framework, generally designated 169, is secured to the plurality of I- beams 165 merely to obscure somewhat the wedge shape so as to give to the door construction the appearance of a straight panel door from the inside of the doorway and to provide a framework for attaching soundproof paneling (not shown). Extending laterally from both sides of the door construction are a pair of heavy wheel housings 171 which are of identical construction so only one need be described. The structure within each of the wheel housings 171 provides the source of power for moving the heavy door construction and generally comprises a supporting structure consisting of l-beams 166 and heavy mounting plate 173. Above the mounting plate 173 is mounted a pair of the door actuators of the present invention and below which is mounted a wheel 175. Each of the wheels 175 rides on a horizontal track 177 which is sunk below the level of the floor line, generally designated 179. Figs. 7 and 8 show in detail the structure within one of the wheel housings 171, Fig. 7 being an enlarged view of the wheel housing on the left-hand side of the door construction, as viewed in Fig. 5. The wheel 175 is rigidly secured to a shaft 181 which is mounted in a pair of inverted pillow blocks 183, each of which is disposed on one side of the wheel 175. Each of the pillow blocks is mounted on a heavy plate member 185 which in turn is secured at one end to the l-beams 165 of the door construction and which is braced to the heavy mounting plate 173 by suitable braces 187 on both sides of the wheel 175.

Two door actuators, each of which is of the same general construction and arrangement previously described, are pivotally suspended from a common shaft 189 which is the main drive shaft for the door construction. The same arrangement is shown as used on both sides of the door construction, in each of the wheel housings 171, although the driving units could be omitted from one side if sufiicient driving power were available for the weight of the door in a given installation. The output shaft as and 15a of each of the door actuators is mounted on one end of the main drive shaft 189 so that the axes of the shafts are in line. Each of the door actuators by its supporting means previously described is pivotally suspended about its own output shaft. The main drive shaft 189 is rotatably supported in a pair of flange bearings 191 and 193. The flange bearing 191 is secured to an upright plate 195 suitably secured to the I-beams 165 of the door construction and to the mounting plate 173. The other flange bearing 193 is mounted on a plate 197 which is secured to one of the I-beams 166 within the wheel housing 171. An intermediate shaft 199 between the main drive shaft 189 and the shaft 181 for the Wheel 175 is rotatably supported at the ends thereof by a pair of flange bearings201 secured to the upright plates 195 and 197.

On the main drive shaft 189 is a sprocket wheel 203 which drives by a suitable chain drive 297 the sprocket wheel 205 secured to the intermediate shaft 199. Also secured to the intermediate shaft 199 is a smaller sprocket wheel 209 which drives a large sprocket wheel 211 by a suitable chain drive 213. The large sprocket wheel 211 is secured to one side of the wheel by suitable means, generally designated 212, so that the sprocket wheel 211 the wheel 175 rotate as a unit.

Power from the motor shaft 13 and 13a of each of the door actuators is thus transmitted through each of the gear boxes 17 and 17a to each of the output shafts 15 and 15a, and to the main drive shaft 189 of the door construction. The power to rotate the main drive shaft 189 is thus approximately doubled through the use of the pair of door actuators. The power supplied to the main drive shaft 189 is transmitted through the intermediate shaft 199 to the sprocket wheel 211 to drive the wheel 175 and by reason of the size of the sprocket wheels employed, there is a speed reduction from the main drive shaft 189 to the shaft 181 to the wheel 175. The same results are obtained of course from the structure within the other wheel housing on the opposite side of the door construction.

Disposed on each side of the track 177 is a pair of guide rollers 215 secured to the door construction by an angle plate 217. The guide rollers 215 are constructed to rotate about vertical axes and are rollably engageable with opposite sides of the track 177 to prevent displacement of the door and keep the wheel 175 on the track 177. The structure within the wheel housing is enclosed by suitable cover plates 219 and to the cover plate which is transversely disposed above the track 177 is secured a wiper 221 which brushes the track clean as the door con struction rolls thereover.

Each of the door actuators functions individually in the manner as described, the combination of the two pairs with each pair being mounted on a common shaft neatly arranged as close as practicable to each wheel so that there is a minimum of power loss in the system contributes to the ease of opening and closing the heavy door construction. In opening, the door construction moves to the right, as viewed in Fig. 6, and in closing it moves to the left and carries with it the two pairs of door actuators which drive it. Each actuator has as an integral part of its assembly the different means previously described, the sensing means 23 associated with the assembly, and the biasing means 21 on one door actuator being shown in Fig. 7. The sensing means 23 and the rigid member 49 of the biasing means in this instance are secured to one end of the door construction 159.

In spite of the large size of the door construction shown in this embodiment, the system is extremely sensitive due to the arrangement described wherein two pairs of actu-- ators separately supply the motive power required to roll the door construction. Reference is made to Fig. 8 wherein it can be seen that the two actuators that make up one of the pairs at each of the ends of the door construction are spaced an unequal distance from the sprocket wheel 203 from which power is derived and about which reactive torque is developed from obstruction to movement of the door construction.

The motors as 11 and 1111 on opposite sides of the system may of course turn in opposite directions or a reversing belt or reversing gears may be used. In any event any undue load will immediately increase the torque demand upon all motors and cause them and their attached gear box structures to swing and operate the safety disabling means as described above. Of course if one is disconnected before the rest, disconnection of that one driving motor will immediately sharply increase the load applied to the others, and cause the safety means of these others to be actuated by virtue of the increased torque loading as described. In such an arrangement, the sensitivity to obstruction to movement of the door construction is exceedingly high in spite of its great weight since only slight movement of but one of the door actuators is required to thereafter abruptly halt movement of the heavy door so as to prevent damage to property or injury to persons.

Shown, by way of example, in Figs. 9 and 10, is the door actuator of the present invention operatively associated with a particular'four-fold door construction. The door actuator is mounted on one side of the four-fold door construction and arranged with respect thereto to drive the same. In the arrangement shown, the door actuator is pivotally suspended about a difierent axis than the axis defined by its output shaft.

Referring to the structure of Figs. 9 and 10 in more detail, the door actuator is suspended in' a framework generally designated 227 secured to the building or other structure in which the door opening is formed and which is disposed above the level of the door panels. The sides of the framework 227 consist of a pair of channel irons 229, vertically disposed and suitably spaced to accommodate .the door actuator. Secured to the channel irons is a pair of parallel support plates 233, each of which has formed centrally therein a pivot support 237 which provides an axis of suspension for the door actuator. To the top of the door actuator assembly is secured a pair of spaced upright plates 239 which have secured therebetween a transversely disposed shaft 241 for supporting the door actuator assembly. The shaft 241 is fixed in the pair of plates 239 against rotation and the ends of the shaft are supported in the pivot supports 237 formed in each of the support plates 233 so that the weight of the door actuator assembly is vertically supported and arranged to pivot on the shaft 241 about the pivot supports 237. The output shaft ofthe door actuator is suitably coupled in a manner similar to that previously described to the main drive shaft 243 for the door construction so as to be concentric therewith. Secured to the main drive shaft 243 is a sprocket wheel 245 which engages an endless chain 225 extending across the center of the door opening and passing over a sprocket wheel 247. The sprocket wheel 247 is suitably mounted on the lintel of the door opening by an outwardly projecting support member 249. Another support member identical in construction to support member 249 and designated 251 is also secured to the door lintel and is suitably spaced from the support member 249 so that the two form end supports for a pair ofslide bars 253, 253a secured near their ends to the support members 249 and 251. The slide bar 253 is disposed below slide bar 253a and each supports and provides a track for slider members 255, 255a, respectively. Each of the slide bars is also centrally supported by a central support member 261 which is also secured to the lintel of the door opening and projects outwardly therefrom. The support members 2 59, 251 and 261- support each of the slide bars from below as by stud members 263, 26511 which allow the slider members 255, 255a to freely pass over the slide bars. The slider members 255 and 255a are each secured to the endless chain 225 which passes axially therethrough and imparts thereto reciprocating motion in opposite directions. The slider members 255, 255a reciprocate in a horizontal plane and are limited in their extent of travel by a pair of limit switches 265. The limit switches 265 are mounted inside the end support members 249, 251 on a pair of horizontal bars 267. Both of the horizontal bars 267 in turn are supported at one of their ends by the central support member 2'61 and one is supported at its other end by end support member 249 while the other is supported at its other end by end support member 251. A cam plate 269 is affixed to the upper slider member 255a to trip an arm 271 on each of the limit switches 265 at the limit of travel of the upper the other half is closed by another unit comprising slider member 255a in opposite directions of its motion. Actuation of the arm 271 opens the contacts of the limit switch to de-energize the EL tor means 11 of the door actuator. De-energization of the door actuator occurs when the door panels are in final closed position and in final open position, as determined by the limit of travel of the upper slider member 255a. In well known manner, the contacts of each of the limit switches are made to close automatically after being actuated to open position so that the door actuator is set up or ready for energization by the start-stop switch to either open or close the doorway as desired.

The doorway is closed by four panels comprising a pair of identical outside panels 273, 273a each of which is hinged to opposite sides of the doorway about vertical pivot axes designated B and B, respectively, and a pair of identical inside panels 275, 275a hinged vertically to the outside panels 2735, 273a, respectively, about pivot axes designated C and C'. The inside panels 275, 275a have free ends 276, 276a, respectively, which meet at the middle of the doorway.

One half of the doorway is thus closed by one comprising outside panel 273 and inside panel 275 unit and outside panel 273a and inside panel 275a operating on opposite hands of the doorway, and since each unit is identical in construction and operation only one will be described. The outside panel 273 hingedly supports in cantilever fashion the inside panel 275 and as the outside panel pivots about pivot axis B it carries with it the hinged side of the inside panel 275 which pivots about pivot axis C. The inside panel 275 thus r'olds against the outside panel and the free end 276 of the inside panel is guided in a track generally designated 277, and therefore follows substantially a path of movement defined by the disposition-of the track 277. The track 277 comprises a pair of parallel rail members 27% which is supported at one end by the central support member 251 and at the other end by outwardly projecting support members 3% which are suitably secured to the building or structure in which the doorway is provided. Intermediate support members 363 are provided which are secured to the lintel of the doorway and are constructed so as to permit the passage of guide rollers 284- betwcen the rail members 278. Similar track structure with parts designated 277a, 278a, etc. is provided on the opposite side of the doorway.

The final open position of the panels of each unit on the sides of the doorways is shown in outline on a reduced scale in the plan view of Fig. 10. The motion for pivoting the outside panel 273 derives from the slider member 255. The outside panel 273 is operatively COL.- nected to slider member 255 by the following linkage. A link arm 279 is pivotally connected to the outside panel as at 276 and to a similar link arm 281 as at 23%. A pivot connection comprising a stud member 283 (Fig. 9) secures the link arm 279 to the outside panel 273 and is itself suitably secured to the top of the panel as at 235. The end of the 'link arm 281 which is not con nected to link arm 279 is pivotally secured to the lintel of the doorway as at 282' by a pivot connection 287 similar to that for link arm 279. The pivot connection 287 for link arm 2&1 however remains stationary while the pivot connection for link arm 279 moves with the movement of the outside panel 273. The link arm 279 is connected to slider member 255 by a pusher rod 2&9. The pusher rod 239 is pivotally secured to the link arm 279 by a suitable link 2% at one end thereof and to slider 255 by a link 297. at the other end thereof. Similar linkage designated 279a, 281a, etc. is provided, of course, for the door unit on the opposite hand of the doorway. The pusher rod 289 thus operates above the door panels and reciprocates in opposite directions by motion imparted to it by the slider member 255. The motion 1 l imparted to the pusher rod 289 is transmitted directly to the link arm 279 and indirectly to the link arm 281 whereby the link arm 231 pivots about its stationary pivot connection 287 to assume the position shown on reduced scale in outline in Fig. for the final open position of the door panels. The link arm 279 concurrently with the movement of link arm 281 turns end for end to assume its final position, also indicated in outline on reduced scale. The free end 276 of the inside panel 275 is guided in its movement by the guide roller 284 which rides in the track 277. The guide roller 234 is disposed so as to be rotatable about a vertical axis and is secured to the free end 276 of the inside door panel by an outwardly projecting connecting member 295 which in turn is suitably secured to the top of the inside door panel 275 as at 297.

In operation, the linkage for movement of the Panels to open and closed position derives its motion, as described, from the slider members 255, 255a which in turn are driven by the endless chain 225. The main drive shaft 243 for the door construction, as described, provides the rotary force for the endless chain 225 and power is transmitted to the main drive shaft 243 by the output shaft of the door actuator which actuates the door panels to open and closed position. Stopping the movement of the door panels at their extreme positions by de-energization of the motor means of the door actuator is independent of the door actuator assembly, as described. Intermediate these final open and closed positions, the door operator assembly functions to insure maximum safety in operation by immediately stopping the movement of the door panels in the event of obstruction in either the opening or closing movement thereof. In normal operation,

the door actuator merely overcomes friction of the moving parts and the reactive torque developed thereby is absorbed by the biasing means 21 which in this instance has for its rigid member one of the pair of upright channel members 229 of the framework 227. The biasing means 21 by the action of its centering spring 51 keeps the door actuator suspended in a substantially central position against ordinary reactive torque. In the event of a more than ordinary load imposed on the output shaft as by obstruction to movement of the door panels in opening or closing, the door actuator will be pivoted from its central position by the increased torque developed about the main drive shaft 243 in opposition to the torque put out by the door actuator assembly. The consequent pivoting of the door actuator or motor transmission assembly actuates the sensing means 23, the contacts of which open to deenergize the motor means for the actuator. The operation of the door actuator in providing this safety feature is substantially the same in the event of obstruction on opening or on closing, and for purposes of explanation of the door actuator with reference to the four-fold door construction shown in Figs. 9 and 10, the operation will be described with reference to closing of the door panels. Assuming that the output shaft of the actuator is rotating in a clockwise direction to close the door panels, the main drive shaft 243 for the four-fold door construction will be also rotating in a clockwise direction and thus driving the endless chain 225 in the same direction. An obstruction, for example, may exert a separating force against both of the inside door panels which will be transmitted to the endless chain in a direction to urge the sprocket wheel 245 and therefore the main drive shaft 243 to rotate in a counterclockwise direction. An unbalanced couple will thus be produced about the main drive shaft 243 for the door construction, and this unbalanced couple exerts a greater than ordinary reactive torque whose axis of application with respect to the door actuator assembly is the axis of suspension of the same so that it will pivot in a counterclockwise direction, as viewed in Fig. 9, and in the instance shown on shaft 241 about pivot supports 233. The axis of application of the reactive torque about which the door actuator pivots being diiferent than the axis defined by its output shaft and the main drive shaft for the door construction necessarily requires that there be allowance for slight displacement of the main drive shaft in order that the door actuator assembly be pivoted. The play inherent between the endless chain and its sprocket wheels provides for this slight movement of the output shaft. It will be understood of course that other means could be provided to accommodate displacement of the main drive shaft when the axis of suspension of the door actuator is different from the axis defined by its output shaft. With reference to driving the four-fold door construction, for example, the output shaft of the door actuator could be directly coupled to a crank arm by suitable adjustment of the linkage for pivoting the panels. The movement of the door actuator from its central position is slight and in most instances can be readily accommodated. Upon movement of the door actuator, the contacts of the sensing means 23 will open to immediately de-energize the motor means 11 whereupon the movement of the door panels will cease, thus preventing injury to persons or damage to property or to the parts of the door construction itself. The other means of the door actuator including the manual means for actuating the door panels in the event of power failure and the brake means to retain the door in its final open or closed position and the disconnect means to put off the brake and take out of circuit the motor means is also included in the door actuator shown associated with the four-fold door construction in Figs. 9 and 10 and their operation and function is substantially as described.

It will thus be seen that there has been provided by this invention a versatile actuator for imparting motion to moving parts in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved.

While it will be apparent that the preferred embodiment of the invention herein described is well calculated to fulfill the objects and advantages first above stated, it will be appreciated that the invention is susceptible to J variation, modification and change without departing.

from the fair meaning and proper scope of the appended claims.

What isclaimed is:

1. An actuator for driving a door or the like comprising a motor-transmission assembly of the reversible drive type having an output shaft, means supporting said assembly for limited pivotal movement about an axis substantially coaxial with the output shaft, means yieldably centering said assembly and opposing such pivotal movement thereof in either direction from a centered position, means for disabling the driving effect of the actuator, and means responsive to pivotal movement of the assembly about said axis beyond a predetermined angle in either direction to activate said disabling means.

2. The combination comprising a main drive shaft for a door construction, a pair of actuators each comprising an assembly as defined in claim 1, one of which is supported at one end of said main drive shaft and the other of which is supported at the other end of said main drive shaft; the output shaft of said one actuator, said main drive shaft and the output shaft of the other said actuator being arranged so as to have their longitudinal axes in line.

3. The combination as defined in claim 2 wherein said door construction comprises a door having Wheels rollably supporting the same and means to mount said main drive shaft and said pair of actuators close to one of said wheels and means to transmit power from said main drive shaft to said one wheel whereby said pair of actuators together supply the motive power for rolling said door construc tion.

4. The combination comprising an actuator as defined in claim 1 and means to mount said actuator at the top of and adjacent a door opening, a door construction comprising a pair 9f doors constructed and arranged to move vertically to open and close said door opening, a counterweight for each of said doors, cable means connecting each of said counterweights to each of said doors, means operatively related to the main drive shaft of said door construction to engage said cable means, said supporting means including means to directly couple said output shaft of said actuator to the main drive shaft for actuating said cable means to drive said pair of doors through open and closed position, said door actuator being arranged with respect to said door construction whereby more than ordinary reactive torque developed about said main drive shaft from obstruction to movement of either of said doors causes said pivotal movement of said door actuator.

5. An actuator for driving a door or the like comprising a motor-transmission assembly having a motor shaft, electric motor means for rotating said motor shaft, an output shaft and a reversible gear drive interconnecting said output shaft and said motor shaft, means supporting said assembly for limited pivotal movement about an axis, said output shaft being displaced from the center of gravity of the assembly, said assembly being bodily rockable about the axis of said shaft by reactive torque developed from driving said door or the like, means biasing said assembly in a central position against reactive torque developed during normal operation and yieldably permitting said assembly to pivot in either direction from said central position by more than ordinary reactive torque developed from obstruction to movement of said door or the like, disabling means for deenergizing said motor means, means responsive to pivotal movement of the assembly about said axis beyond a predetermined angle to activate said disabling means, said motor-transmission assembly further including electric brake means for holding said output shaft. disabling means for said motor means, solenoid means to put off said brake means upon energization of said motor means, and manual means for hand operation of said output shaft including a common actuator for simultaneously actuating said disabling means and releasing said brake means, said gear drive having an input shaft, a pulley wheel secured toone end of said input shaft, clutch means incorporated in said manual means including a sprocket wheel and a hand chain for rotating said sprocket wheel, said manual means also including a bar pivotally secured at one end to said assembly, resilient means urging said bar in a direction whereby to continue application of said brake means, a disconnect chain connected to the free end of said bar for moving the same against the urging of said resilient means to release said brake means, said disconnect means including a switch having a plunger operatively related to said bar whereby predetermined movement of said bar actuates said switch to take out of circuit said motor means.

6. The combination comprising an actuator and a fourfold door construction for closing a door opening, said door construction comprising an outside panel having one vertical edge pivotally connected to one side of said door opening and an inside panel pivotally connected to the other vertical edge of said outside panel, a main drive shaft for said door construction and means including pivotally arranged linkage for pivoting said outside panel about said one side of said door opening whereby said panels fold together to open and assume a coplanar position to close said door opening, said actuator comprising a motor-transmission assembly having an output shaft coupled to said main drive shaft, means for supporting said assembly for limited pivotal movement about an axis parallel and close to said output shaft, said door actuator being constructed and arranged with respect to said door construction whereby more than ordinary reactive torque, developed about said main drive shaft from obstruction to movement of either of said panels, causes said pivotal movement of said actuator, means yieldably opposing said pivotal movement, means for disabling the driving effect of the actuator, and means responsive to pivotal movement of the actuator about said axis beyond a predetermined angle to activate said disabling means.

7. An actuator for driving a door or the like comprising a motor-transmission assembly having a motor shaft, electric motor means for rotating said motor shaft, an output shaft and a reversible gear drive interconnecting said output shaft and said motor shaft, means supporting said assembly for limited pivotal movement about an axis, said output shaft being displaced from the center of gravity of the assembly, said assembly being bodily rockable about the axis of said shaft by reactive torque developed from driving said door or the like, means biasing said assembly in a central position against reactive torque developed during normal operation and yieldably permitting said assembly to pivot in either direction from said central position by more than ordinary reactive torque developed from obstruction to movement of said door or the like, disabling means for cle-energizing said motor means, means responsive to pivotal movement of the assembly about said axis beyond a predetermined angle to activate said disabling means, said motor-transmission assembly further including electric brake means for holding said output shaft, disabling means for said motor means, solenoid means to put oif said brake means upon energization of said motor means, and manual means for hand operation of said output shaft including a common actuator for simultaneously actuating said disabling means and releasing said brake means.

References Cited in the file of this patent UNITED STATES PATENTS 2,533,116 Jenkins Dec. 5, 1950 2,676,294 Wilcox Apr, 20, 1954 2,751,219 Dodge June 19, 1956 2,755,081 Johnson et a1. July 17, 1956 

